There has been an image recording apparatus for recording an image by reciprocating a carriage, which has an ink-jet head (or a recording head) for recording the image on the recording medium by discharging the ink from the nozzles, in a direction perpendicular to the carrying direction of the recording medium. In this ink-jet type image recording apparatus, maintenance operations such as sucking and removing air bubbles reserved in the recording head or dried and solidified ink in the nozzles is carried out. For these operations, a maintenance unit of the image recording apparatus is usually provided outside of a recording area, in which the recording head (or the carriage) is moved relative to the recording medium, and in the vicinity of the moving ends of the recording head (or the carriage)
The maintenance unit has a cap member, which is brought to and away from a nozzle forming face. When the recording head goes out of the recording area to the position of the cap member, the cap member comes into close contact with the nozzle forming face, and suction operation or the like is performed by a suction pump connected to the cap member.
JP-A-3-234644 discloses a configuration in which a cap member made of a flexible rubbery elastomer has a recess corresponding to the openings of a plurality of nozzles and a projection portion (or an outer peripheral rib portion) enclosing the outer periphery of the recess and projecting toward the nozzle forming face. At the maintenance operation time, the projection portion comes into close contact with the nozzle forming face and encloses the openings of the nozzles.
However, the projection portion (or the outer peripheral rib) may have fallen and deformed into the recess due to the action of a vacuum pressure on the recess. In this case, the contact of the cap member with the nozzle forming face is extremely degraded. Thus, the maintenance operations of the recording head cannot be reliably performed.
JP-A-10-34944 discloses a configuration in which a ring-shaped reinforcement member is buried in the recess to abut against the inner peripheral wall of the recess. The reinforce member is made of a more rigid member than the cap member. Therefore, the projection portion (or the outer peripheral rib portion) is hard to fall and deform toward the recess even when a vacuum pressure acts in the recess.